Chronograph



June 20, 1950 W. A. BUCHLER CHRONOGRAPH Filed March 21, 1946 Patented June 20, 1950 Es PATENT OFFICE CHRONOGRAPH Willi A. Biichler, Thoune, Switzerland Application March 21, 1946, Serial No. 655,910

, In Switzerland March 19, 1945 Section 1, Public Law 690, August 8,1946

Patent expires March 19, 1965 This invention relates to chronographs, that is, to timekeepers leaving a record of their going, comprising a winding stem arranged to start, stop and flyback flyback-hands.

" -Anobject of my invention is to induce or release flyback-motion of the fiyback-hands by rotating the winding stem. 7

Other objects and features will be apparent as. the following description proceeds, reference beinglhad to the accompanying drawings, showing by way of example one embodiment of my invention, and wherein Fig. 1 shows the position .-.taken by the organs operating the chronograph when the flyback hands have been stopped in any place, and

Fig. 2 shows the position of a part of said organs including a castle ratchet, after the flyback hands have been brought back.

The numeral 1 indicates the winding pinion in which the click 2 engages, thereby impeding the turning back of said winding pinion which meshes with the wheel 25. This latter engages in the wheel 26 of the winding stem 21 which carries the crown 22. Thus, by rotation of the crown 22 the winding pinion I may be rotated. This click bears a pin 3 which cooperates with the arm 4 of a bent lever 5. This bent lever is pivoted at 6, and its arm I is disposed so that it may modify the position of the bolt 8. This bolt 8 is fixed to a brake member 9 which is formed as a double lever, and is pivoted at It). The resetting or flyback member I2 is pivoted in its turn at H and is submitted to the action of the spring l3, and it is provided with a lip H as well as with a boss [5, that lies on the bolt 8 under conditions mentioned further. The lip l4 engages the hollow spaces of the castle ratchet I1 constituting a fiyback hand-return member, so that the position of the resetting member I2 depends as well on the action of spring 13 as on the castle ratchet l1, said position depending furthermore on the motion of click 2 transmitted to bolt 8.

By pressure upon the crown 22 the castle ratchet I! may be turned through the intermediary of the lever 23 and the pawl 24 mounted on the latter and engaging the teeth of the castle ratchet l1. If by such pressure upon the crown the castle ratchet I1 is brought into a position in which the end 2| of the brake member 9, under the action of spring 20, is allowed to enter a pawl of the castle ratchet, the brake member 9 stops the wheel 28 and thereby the centerseconds hand not shown. On a further pressure upon the crown 22, the castle ratchet H is again turned, and the end 2| or the brake member 9 3 Claims. (01. 58-74) 1 2 disengaged from the space of the ratchet and thereby the wheel 28 and with it the centerseconds-hand released to continue its motion.

The two possible-positions of the resetting member I2 are shown in Figs. 1 and 2. In Fig. 1 it is cooked; that is, the fiyback hands to which the heart-shaped cams l8, l9 belong, having been stopped in any position, said resetting member is ready for bringing them back to their zero position. Fig. 2 relates to the position which it takes after the fiyback hands have been brought back.

The working of the device according to this invention, i. e. the releasing of the cocked reset ting' member by a rotation of the winding stem, will be described by starting from Fig. 1. This Fig. 1 corresponds to the position at which the flyback-hands, for instance a center seconds hand and any other flyback hand, on account of a pressure upon the crown, have just been stopped by the brake. Then the lip 14 of the resetting member I2 is in reach of a hollow space of the castle ratchet or flyback hand-return member IT, at the very time when the resetting member I2 is retained in this position by the bolt 8, which is shoved under the boss l5. If the winding stem is operated in the winding up direction, then the winding pinion rotates in the arrow direction, the click 2 slides along the teeth and is so caused to turn about its fulcrum I6. The pin 3 which is connected fast with the click 2 and therefore moves in the same direction, pushes the bent lever 5 and causes a rotation of said lever about 6. The other arm I is thereby swung out and takes along the bolt 8 in its swinging movement. Now, this bolt motion causes two different efiects. First it releases the brake member 9, since as said already the bolt 8 is rigidly connected with an arm of the brake member 9, which is formed as a double lever and is pivoted in I 0; secondly, the bolt 8 escapes the boss l5 of the resetting member l2, and this member is therefore released. The lip l4 lying in reach of an engaging space of the castle ratchet or fiyback hand-return member H, the resetting member under the action of the spring I3 will rotate and act upon the heart-shaped resetting cams t8 and [9, to turn the latter and thereby to bring back to their zero position the fiyback hands not shown (Fig. 2).

For cooking the resetting member l2, 1. e. in order to bring it back to the position shown in Figure 1, the castle ratchet is rotated by half a pitch by well-known means causing, apart from the releasing of the flyback hands, the raising of the lip l4 out of the engaging space of the castle ratchet. Thereby the bolt 8 snaps again below the boss l5 under the action of the brake spring 20, whereby said resetting member remains seized in this position until the fiyback hands are stopped, i. e. until the castle ratchet is again rotated for half a pitch. Now the relative position of the difierent parts is again that shown in Fig. 1.

What I claim is:

1. In a chronograph, a flyback hand-return member, a pivoted resetting member engageable with and disengageable from said fiyback handreturn member, a stop means for holding said resetting member in disengaged position with regard to said flyback hand-return member, a

winding stem, a toothed wheel, transmission gears connecting said winding stem with said toothed wheel to rotate the latter on rotation of the winding stem, and control means connecting said toothed wheel with said stop means to move the latter out-of holding position with regard to said resetting member on rotation of said winding stem. 7

2. In a chronograph, a fiyback hand-return member, a pivoted resetting member engageable with and disengageable from said flyback handreturn member, a stop means for holding saidresetting member in disengaged position with regard to said fiyback hand-return member, a winding wheel, a click in engagement with said winding wheel, transmission gears connecting said winding stem with said winding wheel to rotate thelatter on rotation of said winding'stem, and control means coupled with said click and said stop means to move the latter out of holding posi- 4 tion with regard to said resetting member on rotation of said winding stem.

3. In a chronograph, a fiyback hand-return member, a pivoted spring-loaded resetting member engageable with and disengageable from said flyback hand-return member, a movable springloaded brake member in disengageable connection with said fiybackhand-return. member, a stop on said brake member engaging said resetting member to 'hold it in disengaged position with regard to said flyback-hand return member on said brake member being in braking position, a windingwheel, a click in engagement with said winding wheel, transmission gears connecting fif tid winding stem with said Winding wheel to rotate the latter on rotation of said winding stem, and a lever engaging said click and said stop to move the latter out of holding position with regard to said resetting member and said brake member out of braking position on rotation of said winding stem,

WILLI A. BUCHLER.

REFERENCES CITED The following references are of record in the fileof this patent:

UNITED STATES PATENTS 

